Temperature sensing system and flow metering apparatus comprised thereof

Abstract

A flow metering apparatus comprising a temperature sensing system for use to measure temperature of fluid includes temperature measurement components and temperature sensing components in close proximity to one another and to the flow of fluid. The components can include a temperature measurement member close-coupled to a processor member, each disposed on a circuitized substrate. This configuration exposes a temperature sensor element to the same dynamic temperature conditions as the processor member, thus reducing measurement error that might manifest in response to different temperature gradients proximate the respective components. A storage memory may be used to permit the temperature sensing system to store and/or retain data that relates to calibration as a dynamic system over the entire operating range of the sensor element. The calibration data may then be accessed from the storage memory to improve accuracy and operation of the flow metering apparatus.

What is claimed is: 
     
       1. A gas meter, comprising:
 a main housing forming a chamber; 
 impellers disposed in the chamber; 
 a first elongate tube with a closed end, the first elongate tube coupled with the main housing and extending into the chamber proximate the impellers so as to locate the closed end in the chamber; 
 a counter housing coupled at one end of the main housing; 
 a host system disposed in the counter housing and configured to calculate volumetric flow; and 
 a temperature sensing system coupled with the host system and disposed entirely in the first elongate tube, the temperature sensing system comprising a first part and a second part that couples with the first part to conduct a digitized output therebetween, 
 wherein,
 the first part comprises a silicon-based integrated circuit having a diode coupled with an analog-to-digital converter that generates the digitized output as a first value for temperature of a fluid in the chamber in response to voltage across the diode, 
 the second part comprises a microcontroller that receives the digitized output, the microcontroller comprising a processor and memory, the memory storing calibration data and executable instructions that the processor can upload, the executable instructions for generating a calibrated signal in response to the digitized output using the calibration data, 
 
 wherein the silicon-based integrated circuit and the microcontroller reside in the first elongate tube in position so that both are exposed inside the chamber and proximate the impellers to ambient temperature that is the same, 
 wherein the calibrated signal reflects a second value for temperature for the fluid in the chamber, which corresponds to the first value calibrated to account for calibration data that correlates ambient temperature at the first part to ambient temperature the second part, 
 wherein the host system receives the calibrated signal and applies the second value for temperature for the fluid in the chamber to the volumetric flow, and 
 wherein the temperature sensing system interrupts operation of the host system to control said gas meter in response to temperature in excess of a pre-determined threshold. 
 
     
     
       2. The gas meter of  claim 1 , wherein the first part and the second part are disposed in the first elongate tube to co-locate in the chamber. 
     
     
       3. The gas meter of  claim 1 , wherein the first part and the second part each comprises a first substrate and a second substrate, respectively, and wherein the first substrate and the second substrate are adjacent one another in the first elongate tube. 
     
     
       4. The gas meter of  claim 1 , wherein the first part and the second part are formed on the same substrate. 
     
     
       5. The gas meter of  claim 1 , wherein the first part comprises:
 a converter element in communication with the silicon-based integrated circuit, the converter element configured to convert an analog signal from the silicon-based integrated circuit to the digitized output. 
 
     
     
       6. The gas meter of  claim 1 , wherein the microcontroller comprises:
 a storage memory configured to store the calibration data and the executable instructions; and 
 a processor coupled with the storage memory, the processor configured to use the calibration data to convert the first value to a second value. 
 
     
     
       7. The gas meter of  claim 1 , wherein the temperature sensing system comprises:
 a second elongate tube that receives the first elongate tube and is in thermal contact with the first elongate tube, wherein the first part is disposed in both the first elongate tube and the second elongate tube. 
 
     
     
       8. The gas meter of  claim 7 , wherein the second part is disposed in both the first elongate tube and the second elongate tube. 
     
     
       9. A gas meter, comprising:
 a main housing forming a chamber; 
 impellers disposed in the chamber; 
 a counter housing coupled at one end of the main housing; 
 a host system disposed in the counter housing and configured to calculate volumetric flow; 
 a first elongate body extending into the chamber proximate the impellers, the first elongate body defining a central cavity, a closed end, and an open end for access to the central cavity; 
 a silicon-based integrated circuit responsive to temperature disposed in the first elongate body so as to reside in the chamber, the silicon-based integrated circuit comprising,
 a diode; and 
 an analog-to-digital converter in communication with the diode to generate a digitized output that corresponds with a first value for a measured temperature in the chamber in response to voltage across the diode; and 
 
 a microcontroller coupled to the analog-to-digital converter and disposed in the elongate body proximate the silicon-based integrated circuit, the microcontroller comprising a processor and a storage memory coupled to the processor and storing calibration data and executable instructions that the processor can upload, the executable instructions for,
 generating a calibrated signal that corresponds with a second value for the measured temperature in response to the digitized output using the calibration data, the calibrated signal correlating ambient temperature proximate the silicon-based integrated circuit to ambient temperature proximate the microcontroller, 
 
 wherein the diode, the analog-to-digital converter, and the microcontroller reside in the elongate body in position so that all are exposed inside the chamber and proximate the impellers to ambient temperature that is the same, 
 wherein the host system receives the calibrated signal and applies the second value for temperature for the fluid in the chamber to the volumetric flow, and 
 wherein the temperature sensing system interrupts operation of the host system to control said gas meter in response to temperature in excess of a pre-determined threshold. 
 
     
     
       10. The gas meter of  claim 9 , wherein the microcontroller is disposed in the central cavity. 
     
     
       11. The gas meter of  claim 9 , wherein the silicon-based integrated circuit and the microcontroller couple with the first elongate body. 
     
     
       12. The gas meter of  claim 9 , wherein the silicon-based integrated circuit and the microcontroller reside on a circuitized substrate. 
     
     
       13. The gas meter of  claim 12 , wherein the circuitized substrate comprises a first substrate and a second substrate, one each for the silicon-based integrated circuit and the microcontroller.